菜鸟问题，nameerror print_all is not defind

[qq_34077336]

from sys import argv

script, input_file = argv

def rewind(f):
print f.read()

def rewind(f):
f.seek(0)

def print_a_line(line_count,f):
print line_count, f.reading()

current_file = open(input_file)

print"First let's prin the whole file :\n"

print_all(current_file)

print"Now let's rewind,kind of ilke a tape."
rewind(current_file)

print"Let's print three lines."

current_line = 1
print_a_line(current_line,current_file)
current_line = cuurent_line + 1

current_line = current_line + 1
print_a_line(current_line,current_file)

current_line = current_line + 1
print_a_line(current_line,current_file)